Rebuilding a new set of George's "REBUILT" Carburetors

[OldVet66]

The one that needs the X shim is too tight with a 2.60mm shim, yes it might just make the .03mm, it's too loose with the 2.55, (.10mm). These adjustments are all over the board and will not get close with any combination I have tried. If I had all the sizes, I could dial them all in to a specific value within the acceptable range and I would feel comfortable with that. This motor is an unknown, from Ebay. I don't understand the erratic wear on this motor. I suspect I will see a more even wear pattern on the motor I pulled today. If that is the case, the Ebay motor may have been a Frankenstein assembly of odds and ends from other motors, explaining the strange wear pattern. This is the first one I have tried, and I don't know what is normal or not. I would think all values within the specs. should be adjusted to be the same, or is that an impossible task with these motors.

[Steve]

The one that needs the X shim is too tight with a 2.60mm shim, yes it might just make the .03mm, it's too loose with the 2.55, (.10mm). ...

If a 2.55 shim makes it .10mm clearance, a 2.60 should make it .05mm.

If it was my engine, I would run the 2.55.

.

[OldVet66]

It should, but it doesn't. I've even had my friend set it up to avoid me making the same stupid mistake every time, and it's too tight for the .05mm gauge with a 2.60 shim in there. Tried several different 2.60 shims, and will be ordering another gauge from trying to make it do what it's supposed to do. .10mm was an easy fit with a long feeler gauge, apposed to the easier to use angled gauges (can see why they sell them in cards of 6). The gap could have been a little wider.

[KEITH KRAUSE]

You have to use the correct feeler gauge or it complicates things. Using a gauge that doesn't go down to .03 just makes it more difficult. I know it doesn't make much sense but I too have often found that even a "wide" .08 measurement that should become a .03 when the next thinner shim is used just won't allow the gauge to slip in. I've cycled the motor to "set" the new shim if you will and still get a read that contradicts what should be. I always go with the .08 in this case.
I wouldn't go outside the factory range of .03 to .08. Guess I've been lucky. I found X shims locally years ago. Only needed a couple. Typically, a 2.55 X shim is really 2.57 or at the most and less frequently 2.58. Same difference for all the sizes. They come in very handy and can help you fine tune the clearances and avoid being right at the minimum or maximum clearance.
What's exactly happening in your case I'm not sure, especially when you say you've tried several shims stamped the same thickness. What I said above about it not making sense is just the way it is and using that .05 gauge is adding to that. If you're sure you're taking the measurement correctly (factory procedure and oiled shim) I'd measure the 2.60 shim with calipers or verniers to verify. Then verify the 2.55. If both are correct, then you can be sure the .10 clearance will become .05 or very close (certainly not less than .03) when you swap the 2.55 for the 2.60. If you were using the right thickness gauge you wouldn't be having this issue.

[OldVet66]

I'm pretty sure of those measurements. I do have a gauge that goes to .03mm, but it's not like the nice angled one from Z1. I suppose I will have to sacrifice a standard set and make one so I can accurately check all possibilities. Using the proper type of gauge makes all the difference in the world. I might be able to check the '79 motor tonight, but I have a leaking hot water heater that needs immediate replacing before we have a real mess.

[OldVet66]

It seems that things are finally looking up for a change. I got a look at the motor on the '79 today. Absolutely no sign of wear on the cams. All the valves are in spec., .05mm and .08mm. The bike this motor came from had 3,802 miles on it. Either the first valve adjustment was done just before it was parked, or it didn't need one. The motor had been fogged down before storage. I will swap motors this weekend and run a compression test. I'll go back through the carburetors and check the floats and do a proper bench sync. We have a Color Tune, but it might be several weeks before I can order the Morgan Carb Tune manometer. Finally moving forward.

[KEITH KRAUSE]

Good deal. Let us know if you need help.

[OldVet66]

Had a bit of a long day today. Spread the tarps out in the driveway parked the bike to one side, hauled the new motor up beside it and proceeded to change the motor. got properly sunburned in the process. I don't have a timing light yet, so I scribed around the washers on the plate for my Dyna S ignition, so I could get it close. fast forward to the end of the day with everything assembled, primed the carbs gave it a little choke, and it fired immediately. This motor is sweet. I installed my new carb boots, used Rotella T 15W40. The front sprocket on this motor has 14 teeth apposed to the 16 teeth on the other motor. It has lots more low end power, hope it doesn't effect mileage too much, I'm liking it. Next stage is to sync the carbs. I still have to order the Morgan Carb Tune, so It will be a little while until I'm ready to sync it.